反应详情

Dabigatran etexilate was first described in U.S. Pat. No. 6,087,380, according to which the synthesis of dabigatran etexilate was carried out in three synthetic steps (see Scheme 1). Example 58 describes the condensation between ethyl 3-{[3-amino-4-(methylamino)benzoyl](pyridin-2-yl)amino}propanoate (compound II) and N-(4-cyanophenyl)glycine (compound III) in the presence of N,N′-carbonyldiimidazole (CDI) in tetrahydrofuran to give the hydrochloride salt of ethyl 3-{[(2-{[(4-cyanophenyl)amino]methyl}-1-methyl-1H-benzimidazol-5-yl)carbonyl](pyridin-2-yl)amino}propanoate (compound IV), which is subsequently reacted with ethanolic hydrochloric acid, ethanol and ammonium carbonate to give the hydrochloride salt of ethyl 3-{[(2-[{(4-carbamimidoylphenyl)amino]methyl}-1-methyl-1H-benzimidazol-5-yl)carbonyl](pyridin-2-yl)amino}propanoate (compound V). Finally, example 113 describes the reaction between compound V and n-hexyl chloroformate (compound VI), in the presence of potassium carbonate, in a mixture of tetrahydrofuran and water, to give dabigatran etexilate after work-up and chromatographic purification. However, no information is given about the purity of the isolated dabigatran etexilate.